This disclosure relates generally to printing machines. More particularly, the present disclosure relates to fuser assemblies for electrographic or xerographic copying or printing devices.
In a typical electrographic or xerographic copying or printing process, a charge retentive surface such as a photoconductive member is charged to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoconductive member is selectively exposed to light to dissipate the charges thereon in areas subjected to the light. This records an electrostatic latent image on the photoconductive member. After the electrostatic latent image is recorded on the photoconductive member, the electrostatic latent image is rendered visible by bringing one or more developer materials into contact therewith. Generally, the developer material comprises toner particles adhering triboelectrically to carrier granules. The toner particles are attracted from the carrier granules either to a donor member or to a latent electrostatic image on the photoconductive member. When attracted to a donor member, the toner particles are subsequently deposited on the latent electrostatic images. The toner powder image is then transferred from the photoconductive member to a final substrate or imaging media. The toner particles forming the toner powder images are then subjected to a combination of heat and/or pressure to permanently affix the powder images to the substrate.
A fuser assembly is commonly used to heat the toner material and cause it to fuse to the substrate. The assembly includes a fuser roller that rotates around an axis as the substrate is drawn between it and a pressure roller. Heat is applied to the toner material via the fuser roller during this drawing process. Fuser rollers typically operate at temperatures up to approximately 200° C.
In high quality production printing it is extremely difficult to design a fuser roller that is optimum for all the possible applications that may be seen. As a result compromises and tradeoffs have to be made in the fuser roller design so that acceptable performance is achieved over the wide range of jobs that may be run. The result is higher cost and perhaps lower quality output than otherwise would have been achieved if a fuser roller was available that was specifically tailored for the particular application.
The main obstacles to implementing custom application fuser rollers are the difficulty in managing the inventory of custom fuser rollers that would be required and preventing the wrong roller being used for the application being run.